High-Power Laser-Plasma Interaction

"Laser power has increased from 100 watts in 1960 (the first laser) to terawatts in 1985 through the invention of chirped pulse amplification proposed by Mourou and Strickland, to 100 petawatt and beyond today. Presently, lasers constitute the most powerful coherent source of radiation on the Earth. Also, we have advanced our understanding of the most fascinating but complex state of high-temperature matter, plasma, in which matter is ionized to contain free electrons and ions. Plasma supports many collective oscillations, such as electron plasma waves and ion acoustic waves, and the electromagnetic wave is also strongly modified by plasma. Parametric coupling between lasers and plasma waves and quasi-modes gives rise to stimulated Raman, Brillouin and Compton scattering, two-plasmon decay, and four-wave processes including filamentation, modulational and oscillating two-stream instabilities. Nonlinear refraction leads to self-focusing and self-guiding of the laser over long distances in plasma and air, offsetting diffraction divergence. Laser interaction with metallic surfaces gives rise to surface-enhanced Raman scattering from adsorbed molecules and mode conversion to surface plasma waves with application to ablation and thin film deposition. With the rapid development of laser technology and plasma understanding, we can expect many exciting new frontiers of research to develop in coming years"--